How can I uninstall FoxTab -- disabling and deleting it under add-ons does NOT get rid of this malware!

FoxTab is malware. It snuck into my browser through an audio converter. Following the directions for deleting an add-on in Firefox doesn't get rid of it -- meaning, I've deleted the add-on, but it's still there when I open Firefox.
So -- what else needs to be done to get rid of FoxTab?

FoxTab is malware. It snuck into my browser through an audio converter. Following the directions for deleting an add-on in Firefox doesn't get rid of it -- meaning, I've deleted the add-on, but it's still there when I open Firefox.
So -- what else needs to be done to get rid of FoxTab?